1 /* 2 * $Id: pa_memorybarrier.h 1240 2007-07-17 13:05:07Z bjornroche $ 3 * Portable Audio I/O Library 4 * Memory barrier utilities 5 * 6 * Author: Bjorn Roche, XO Audio, LLC 7 * 8 * This program uses the PortAudio Portable Audio Library. 9 * For more information see: http://www.portaudio.com 10 * Copyright (c) 1999-2000 Ross Bencina and Phil Burk 11 * 12 * Permission is hereby granted, free of charge, to any person obtaining 13 * a copy of this software and associated documentation files 14 * (the "Software"), to deal in the Software without restriction, 15 * including without limitation the rights to use, copy, modify, merge, 16 * publish, distribute, sublicense, and/or sell copies of the Software, 17 * and to permit persons to whom the Software is furnished to do so, 18 * subject to the following conditions: 19 * 20 * The above copyright notice and this permission notice shall be 21 * included in all copies or substantial portions of the Software. 22 * 23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 26 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR 27 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF 28 * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 29 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 30 */ 31 32 /* 33 * The text above constitutes the entire PortAudio license; however, 34 * the PortAudio community also makes the following non-binding requests: 35 * 36 * Any person wishing to distribute modifications to the Software is 37 * requested to send the modifications to the original developer so that 38 * they can be incorporated into the canonical version. It is also 39 * requested that these non-binding requests be included along with the 40 * license above. 41 */ 42 43 /** 44 @file pa_memorybarrier.h 45 @ingroup common_src 46 */ 47 48 /**************** 49 * Some memory barrier primitives based on the system. 50 * right now only OS X, FreeBSD, and Linux are supported. In addition to 51 *providing memory barriers, these functions should ensure that data cached in 52 *registers is written out to cache where it can be snooped by other CPUs. (ie, 53 *the volatile keyword should not be required) 54 * 55 * the primitives that must be defined are: 56 * 57 * PaUtil_FullMemoryBarrier() 58 * PaUtil_ReadMemoryBarrier() 59 * PaUtil_WriteMemoryBarrier() 60 * 61 ****************/ 62 63 #ifndef MODULES_THIRD_PARTY_PORTAUDIO_PA_MEMORYBARRIER_H_ 64 #define MODULES_THIRD_PARTY_PORTAUDIO_PA_MEMORYBARRIER_H_ 65 66 #if defined(__APPLE__) 67 #include <libkern/OSAtomic.h> 68 /* Here are the memory barrier functions. Mac OS X only provides 69 full memory barriers, so the three types of barriers are the same, 70 however, these barriers are superior to compiler-based ones. */ 71 #define PaUtil_FullMemoryBarrier() OSMemoryBarrier() 72 #define PaUtil_ReadMemoryBarrier() OSMemoryBarrier() 73 #define PaUtil_WriteMemoryBarrier() OSMemoryBarrier() 74 #elif defined(__GNUC__) 75 /* GCC >= 4.1 has built-in intrinsics. We'll use those */ 76 #if (__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1) 77 #define PaUtil_FullMemoryBarrier() __sync_synchronize() 78 #define PaUtil_ReadMemoryBarrier() __sync_synchronize() 79 #define PaUtil_WriteMemoryBarrier() __sync_synchronize() 80 /* as a fallback, GCC understands volatile asm and "memory" to mean it 81 * should not reorder memory read/writes */ 82 /* Note that it is not clear that any compiler actually defines __PPC__, 83 * it can probably removed safely. */ 84 #elif defined(__ppc__) || defined(__powerpc__) || defined(__PPC__) 85 #define PaUtil_FullMemoryBarrier() asm volatile("sync" ::: "memory") 86 #define PaUtil_ReadMemoryBarrier() asm volatile("sync" ::: "memory") 87 #define PaUtil_WriteMemoryBarrier() asm volatile("sync" ::: "memory") 88 #elif defined(__i386__) || defined(__i486__) || defined(__i586__) || \ 89 defined(__i686__) || defined(__x86_64__) 90 #define PaUtil_FullMemoryBarrier() asm volatile("mfence" ::: "memory") 91 #define PaUtil_ReadMemoryBarrier() asm volatile("lfence" ::: "memory") 92 #define PaUtil_WriteMemoryBarrier() asm volatile("sfence" ::: "memory") 93 #else 94 #ifdef ALLOW_SMP_DANGERS 95 #warning Memory barriers not defined on this system or system unknown 96 #warning For SMP safety, you should fix this. 97 #define PaUtil_FullMemoryBarrier() 98 #define PaUtil_ReadMemoryBarrier() 99 #define PaUtil_WriteMemoryBarrier() 100 #else 101 # error Memory barriers are not defined on this system. You can still compile by defining ALLOW_SMP_DANGERS, but SMP safety will not be guaranteed. 102 #endif 103 #endif 104 #elif (_MSC_VER >= 1400) && !defined(_WIN32_WCE) 105 #include <intrin.h> 106 #pragma intrinsic(_ReadWriteBarrier) 107 #pragma intrinsic(_ReadBarrier) 108 #pragma intrinsic(_WriteBarrier) 109 #define PaUtil_FullMemoryBarrier() _ReadWriteBarrier() 110 #define PaUtil_ReadMemoryBarrier() _ReadBarrier() 111 #define PaUtil_WriteMemoryBarrier() _WriteBarrier() 112 #elif defined(_WIN32_WCE) 113 #define PaUtil_FullMemoryBarrier() 114 #define PaUtil_ReadMemoryBarrier() 115 #define PaUtil_WriteMemoryBarrier() 116 #elif defined(_MSC_VER) || defined(__BORLANDC__) 117 #define PaUtil_FullMemoryBarrier() _asm { lock add [esp], 0} 118 #define PaUtil_ReadMemoryBarrier() _asm { lock add [esp], 0} 119 #define PaUtil_WriteMemoryBarrier() _asm { lock add [esp], 0} 120 #else 121 #ifdef ALLOW_SMP_DANGERS 122 #warning Memory barriers not defined on this system or system unknown 123 #warning For SMP safety, you should fix this. 124 #define PaUtil_FullMemoryBarrier() 125 #define PaUtil_ReadMemoryBarrier() 126 #define PaUtil_WriteMemoryBarrier() 127 #else 128 # error Memory barriers are not defined on this system. You can still compile by defining ALLOW_SMP_DANGERS, but SMP safety will not be guaranteed. 129 #endif 130 #endif 131 132 #endif /* MODULES_THIRD_PARTY_PORTAUDIO_PA_MEMORYBARRIER_H_ */ 133